CPU 150 performs a matrix operation on image data GD, and then increases the effective digit place number of the color values of the image data GD to increase the tone number of the image data GD from 8-bit tone to 18-bit tone. CPU 150 performs a gamma correction process, a matrix operation N−1M, and an inverse gamma correction process, and then restores the tone number of the image data GD to the original 8-bit tone, and performs automatic quality adjustment. As a result, the 8-bit tone of the original image data GD is preserved throughout image processing, and reproductive color number of the image data GD is preserved as well.
Legal claims defining the scope of protection, as filed with the USPTO.
1. An image processing apparatus for performing image processing of image data, said image processing apparatus comprising: a color converter for converting by use of a matrix operation image data of a first color system in a first color coordinate system, said first color system capable of representing a first color number, to image data of a second color system in a second color coordinate system, said second color system capable of representing a second color number more numerous than the first color number, while preserving the first color number; an image processor for performing image processing on the converted image data in the second color system; and a reproductive color number reducer for reducing the reproductive color number of image data subjected to the image processing.
2. An image processing apparatus according to claim 1 wherein image processing performed by the image processor includes gamma correction processing.
3. An image processing apparatus according to claim 2 wherein the first color system is the YCC color system, and the second color system is the sRGB color system.
4. An image processing apparatus according to claim 1 wherein the second color number of the second color system includes a color number represented by a negative value included in image data converted by the color from the first color system to the second color system.
5. An image processing apparatus according to claim 4 wherein image processing performed by the image processor includes gamma correction processing.
6. An image processing apparatus according to claim 4 or 5 wherein image processing performed by the image processor includes color conversion processing using a second matrix operation.
7. An image processing apparatus according to claim 4 wherein the first color system is the YCC color system, and the second color system is the wRGB color system having a wider color representation range than the sRGB color system.
8. An image processing apparatus for performing image processing on image data, said image processing apparatus comprising: a first image processor for modifying a color value of the image data represented by an integral value having first effective digits into a first value having a greater place number than the place number of the first effective digits; a tone number reduction preventer for preventing reduction of tone number of the image data accompanying modification of color value by the first image processor; and a second image processor for modifying the color values of image data having the first value from the first value to a second value reflected in image output results.
9. An image processing apparatus according to claim 8 wherein the tone number reduction preventer prevents reduction of tone number of the image data by setting the effective digits of the first value to a greater place number than the place number of the first effective digits.
10. An image processing apparatus according to claim 9 wherein the data size of image data prevented by the tone number reduction preventer from tone number reduction is larger than the data size of image data represented by integers having the first effective digits.
11. An image processing apparatus according to any of claims 8 to 10 wherein the first image processor is color space convener for convening the color space of the image data from a first color space to a second color space.
12. An image processing apparatus according to claim 11 wherein the color space converter converts the color space of the image data from the YCbCr color space to the RGB color space, and modifies a color value of the image data represented by integers having the first effective digits to the first value that includes a decimal point.
13. An image processing apparatus for performing image processing on image data, said image processing apparatus comprising: a first color space converter for increasing the tone number of the image data from a first tone number to a second tone number, as well as converting the color space of image data from the YCbCr color space to the sRGB color space; a gamma corrector for performing gamma correction on the color space-converted image data; a second color space converter for converting the color space of gamma-corrected image data from the RGB color space to a wRGB color space having a wider defined range than the sRGB color space; and a tone number reducer for restoring tone number of the color space-converted image data from the second tone number to the first tone number.
14. An image processing apparatus according to claim 13 further comprising: an inverse gamma corrector for performing inverse gamma correction on the color space-converted image data; wherein the tone number reducer restores the tone number of the inverse gamma-corrected image data, rather than the color space-converted image data, from the second tone number to the first tone number.
15. An image processing apparatus according to claim 14 further comprising: an image corrector for automatically correcting quality of the inverse gamma corrected-image data; wherein the tone number reducer restores the tone number of the quality-corrected image data, rather than the inverse gamma-corrected image data, from the second tone number to the first tone number.
16. A printing apparatus for outputting image-processed image data, said printing apparatus comprising: the image processing apparatus according to claim 1 or any of claims 8 , 9 , 10 , or 12 , and an output for outputting image data subjected to image processing by the image processing apparatus.
17. A computer-readable medium having recorded thereon an image processing program for performing image processing on image data, wherein the image processing program realizes by means of a computer: a function for converting by means of a matrix operation image data of a first color system in a first color coordinate system, said first color system capable of representing a first color number, to image data of a second color system in a second color coordinate system, said second color system capable of representing a second color number more numerous than the first color number, while preserving the first color number; a function for performing image processing on the converted image data in the second color system; and a function for reducing the reproductive color number of image data subjected to the image processing.
18. A computer-readable medium according to claim 17 wherein the second color number of the second color system includes a color number represented by a negative value included in image data converted from the first color system to the second color system by the color converting function.
19. A computer-readable medium according to claim 18 wherein the function for performing image processing is a function for executing at least one process selected from gamma correction and color conversion using a second matrix operation.
20. A computer-readable medium according to claim 18 wherein the first color system is the YCC color system, and the second color system is the wRGB color system having a wider color representation range than the sRGB color system.
21. A computer-readable medium having recorded thereon an image processing program for performing image processing on image data, wherein the image processing program realizes by means of a computer: a first image processing function for converting a color value of the image data represented by an integral value having first effective digits into a first value having a greater place number than the place number of the first effective digits; a function for preventing reduction of tone number of the image data accompanying modification of color value by the first image processing function; and a second image processing function for modifying a color value of image data having the first value from the first value to a second value that is reflected in image output results.
22. A computer-readable medium according to claim 21 wherein the preventing of reduction of tone number is realized by setting the effective digits of the first value to a greater place number than the place number of the first effective digits.
23. A computer-readable medium according to claim 22 wherein the data size of image data prevented by the tone number reduction preventing means from tone number reduction is larger than the data size of image data represented by integers having the first effective digits.
24. A computer-readable medium according to claim 22 or 23 wherein the first image processing function is color space converting function for converting the color space of the image data from a first color space to a second color space.
25. A computer-readable medium according to claim 24 wherein the color space converting function converts the color space of the image data from the YCbCr color space to the RGB color space, and modifies a color value of the image data represented by integers having the first effective digits to the first value that includes a decimal point.
26. A computer-readable medium having recorded thereon an image processing program for performing image processing on image data, wherein the image processing program realizes by means of a computer: a first color space converting function for increasing the tone number of the image data from a first tone number to a second tone number, as well as converting the color space of image data from the YCbCr color space to the sRGB color space; a gamma correcting function for performing gamma correction on the color space-converted image data,; a second color space converting function for converting the color space of gamma-corrected image data from the sRGB color space to a wRGB color space having a wider defined range than the sRGB color space; and a tone number reducing function for restoring the tone number of the color space-converted image data from the second tone number to the first tone number.
27. A computer-readable medium according to claim 26 wherein the image processing program further realizes by means of a computer: an inverse gamma correcting function for performing inverse gamma correction on the color space-converted image data; wherein the tone number reducing function is a function for restoring the tone number of the inverse gamma-corrected image data, rather than the color space-converted image data, from the second tone number to the first tone number.
28. A computer-readable medium according to claim 27 wherein the image processing program further realizes by means of a computer: an image correcting function for automatically correcting quality of the inverse gamma corrected-image data; wherein the tone number reducing function restores the tone number of the quality-corrected image data, rather than the inverse gamma-corrected image data, from the second tone number to the first tone number.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
March 14, 2002
August 7, 2007
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